Due into the increasing complexity of the current supply required by microprocessors in, for example, motherboards for computers and notebooks, multi-phase dc-dc buck converters are provided. A current of 2 to 20 amps can typically be provided by each phase of the buck converter. A buck converter typically comprises one or more half-bridge circuits, each provided by two power semiconductor power switches, such as power MOSFET devices, and further passive components, such as an inductance and a capacitance. The switching of the power MOSFET devices is controlled by a control semiconductor chip.
The components of the buck converter may be provided as individual components which are mounted on a printed circuit board. Alternatively, a number of components accommodated in a single housing to provide a multi-chip module, also referred to as a System-in-Package (SiP), which has the advantage that the assembly of the module on the board is simplified and the space required on the board can be reduced.
Due to the increasing demands for smaller components and higher power, insufficient heat dissipation from multi-chip modules may deleteriously affect the functionality of the module and/or neighboring components on the board. Improved heat dissipation from multi-chip modules is, therefore, becoming increasingly important.